Bio:In the earliest black-and-white Mirage Comics Raphael was the most violent turtle and had a tendency for going berserk either in battle or when his temper flared up. He was possibly meant to be something of an answer to the X-Men's Wolverine. Even his sai resemble Wolverine's claws, and Raphael occasionally holds them so that it really looks like he has claws. Raphael has a somewhat cynical and sarcastic sense of humor.

Raphael mellowed somewhat as the series went on; possibly a key moment for his character development was when he allowed Leonardo alone to defeat The Shredder in Issue 21 of Volume 1. Since then he has been less likely to challenge Leonardo’s leadership, and on the whole is more friendly towards his family and allies.

Out of his three brothers Raphael is closest to Michelangelo, even having stated it in the fourth issue of the original TMNT comics. In his self-titled one-shot micro series Raphael met human vigilante Casey Jones, his foil, who was even more violent and unstable than he was. Despite their brutal first meeting, the two have since formed a close bond.

In the 2001 comic book series (Volume 4), he is still the most violent turtle, but is also more social and less bitter. After having been bitten by what may or may not have been vampires, he has experienced a further mutation, becoming an enormous, dinosaur-like version of himself.